Tuning gear for radio receiving sets



Feb. 27, 1940.. KAMENAROWC 2,192,084

TUNING GEAR FOR RADIO RECEIVING SETS Filed June 19, 1937 Patented Feb. 21', 1940 Leone Kamenarovic, Milan, Italy, assign or to Fabbrica Italiana" Magneti Marelli Societa Anonima, Milan, Italy, a corporation of Italy Application June-19, 1887, SeriaLNo. 149,288

. In Italy June 25, 1936 '5 Claims. 74-10) The present invention relates to two-ratio traon gears for the tune control in radio receiving sets.

In the gear of this invention the control of the tuning means is eflected under two diflerent tran ratios one of which is devoted to coarse tuning manipulations while the other one is devoted to Vernier manipulations of said tuning means; for the above stated purpose said gear includes a rotatable tuning knob which cooperates with a certain angularlost motion with a part actuating the tuningmeans and a reducing gear operative on said part and having a frictionally slipping member this reducing gear being operative under the drive of said knob within the ranges of said lost motion thereof.

The present invention includes a simple construction with a reducing gear of planetary type.

which provides for a proper reducing ratio in go the drive through it with a simple and small size arrangement; further it includes provisions for making the whole gear simple and for securing a satisfactory operation.

Two embodiments of the present invention are illustrated by way of example on the annexed drawing and Fig. 1 is a fragmentary longitudinal section of a first construction,

Fig. 2 is a transverse section on line 2-2 of '0 Fig. 1, and

I Fig. 3 is a fragmentary longitudinal section of a modified construction.

In construction of Figures 1 and 2 the tune control hiob I is fast with a spindle 2 which is mounted to rotate in bearings as 3 of a stationary support frame 4; a sleeve 5 is loose on the shaft 2 and has a cord-winding drum 6 provided thereon, and a cord 2| devoted to the control of the tuning means and associate dial (not shown) is attached to said drum for being wound onand paid off from it. v

The knob l is pnovided with a finger 'Iadapted to engage a finger 8 extending from the sleeve 5 and having a restricted peripheral extent to provide for a wide angular lost motion of finger I and knob l with respect to finger 8 and sleeve 51 A cup shaped rim l8 encircles the sleeve 5 and spindle 2 and is fastened on the frame 4 by means of screws 8 and spacing collars It; an annular disc Ii is slidably supported on collars I0 adjacent the cup rim l8 and forced towards it by means of a spring spider l2 whose arms abut on the heads of screws 8 while the central annular portion of said spider exerts a pressure 5 on the disc ll tourge it towards the cup rim l8.

Two opposed conical rings l8 and I8 are located intermediate thecup l8 and disc II and friction linings l8 and it are located intermediate the cup l8 and ring I! on one side and intermediate ring I 8 and disc II on the other side: a said rings 15 and I8 provide an intermediate groove 25 opening towards the spindle 2 and in register with said groove 25 the sleeve 5 has holes 5' in each of which is located a ball l'l engaging the opposite surfaces of spindle 2 and rings In operation when the rotary knob I is manipulated in either direction,- when its finger I engages directly the finger 8 of the sleeve 5 said sleeve 5 is driven directly,by the knob l with ru the drum 6 and cord 2i and thus the coarse control of the tuning means and dial is obtained; in this operation the balls II are driven directly by the sleeve 5 being engaged in seats 5' thereof and with the spindle 2 and they drive in turn the rings l8 and I8 in rotation, said rings i5, i8 frictionally slipping over the respective linings l3 and I4.

To carry out the vemier tuning operation the knob i is manipulated in a direction to cause the a finger I thereof to move off from the face of finger 8 contacted thereby. Then the sleeve 5 is released from knob I and said knob by means of the spindle 2 fast therewith causes a gyratory motion of the balls I! within their seats 5' in the m sleeve 8 said balls I! thus rolling on the coopcrating surfaces of rings i5 and it; at this time the rings l8, ii are stationary they being frictionally engaged by linings l3 and M which are clamped between the disc ii and cup rim I8 85 under the action of the spring spider l2.

In these conditions the sleeve '5 and drum 8 are driven in revolution over spindle 2 by the planetary or gyratory operation of the balls under the reducing ratio provided by the plane- 40 tary gear consisting of parts 2, l1, l5, l6.

In the above described construction the part of the planetary gear which is to be stationary in the planetary operation (as rings l5, I8) is held stationary by separate means devoted to' 45 such purpose as linings l3 and it, but this invention includes also an arrangement in which said part is held stationary for such purpose by the frictional action usually occurring between the several parts under the action of forces in- 50 herent to the operation of the gear, as the couple of reaction forces due to the pull of the cord operating the tuning means and dial.

A construction of this kind is illustrated in Fig. 3 in which the arrangement is substantially identical with that illustrated in Figures 1 and 2, the members being denoted by the references applied to equivalent ones of Figures 1 and 2. In the construction of Figure 3 the stationary parts I8, 9, III, II, I! and friction linings l3, M

are omitted,'while the ring I6 which cooperates with ring I to provide the groove 25 where balls I! are rolling. during their planetary operation under the drive of knob I, spindle 2 and spindle groove 2' where said balls I I are engaged, and is located on the opposed side to drum 6 with respect to said balls I1 and associate ring l5, has

a sleeve I 6' rotatable in an extended bearing tv forced towards each other to engage the balls I! intermediate them by means of a resilient corrugated or wave shaped ring 20 abutting on a flange I6" of ring l6 and a ring l9 which in turn is engaged with a flanged rim l 5' of ring I5.

When the knob I is manipulated with spindle 2 and the finger 1 fast with the spindle 2 and knob I engages the finger 8 of sleeve 5, the drum 6 is positively driven with sleeve 5, balls I'I, rings I5 and I6 and sleeve I6 which slips within the bear-' ing 4'; on the contrary during the vernier manip ulation that is when the spindle 2 is caused by the operators manipulation of knob I to rotate with respect to sleeve 5, the frictional engagement of parts 4' and I6 with each other is sufficient to hold the rings I5, I6 stationary and accordingly the balls I! are caused to roll over said rings and to drive the sleeve 5 and drum 6 under a slow or reduced ratio.

The frictional engagement of the parts I6 and '4' may be magnified by means of suitable linings as 22 and 23 which are operative respectively intermediate the parts I6 and l and part I and a split annulus 24 fast on sleeve I 6'.

In both constructions the drive of the tuning means and dial under the ratio provided for the vernier adjustment by the planetary gear occurs through an angle corresponding to a full revolution of the knob I more the angle through which the sleeve 5 has moved under the planetary action and less an angle depending upon the angular extents of fingers I and 8. I

The tuning operation is effected by manipulating the knob I to carry the finger 1 into engagement with the finger 8 for rotation of the sleeve 5 and drum 6 in the direction in which the tuning means and dial are moved towards the desired tune position andsaid knob I and parts controlled thereby are further rotated in said direction until they are somewhat beyond the desired tuning position; then the knob I is operated in reverse direction to release the finger I from finger 8 and to carry out the vernier tune adjustment with the cooperation of the planetary gear until the correct tuning adjustment is secured.

What I claim as my invention and desire to secure by United States Letters Patent is:

1. A tuning control device for radio receivers comprising a manipulating knob, a part connected with said knob, a second part concentric with the first named part, planet means intermediate said parts, a driven member engaged with said planet means, connecting means engaged with said -member for actuating the radio receiver tuning means and dial, means on said first named part and driven member for their direct interen-' gagement with wide angular lost motion, astationary part, said second part and stationary part having cooperating friction surfaces and said connecting means being operative on said member and second part to hold said friction surfaces interengaged and said second part stationary during the drive of said driven member through said planet means and to provide for slip motion of said second part when said knob and first-named part drive directly said driven member.

2. A tuning control device for radio receivers comprising a manipulating knob, a part connected with said knob, a second part concentric with the first named one, planet means intermediate said parts, a driven member engaged with said planet means, a cord operating the radio receiver tuning means and dial and operatively connected with said hollow member, means on said first named part and driven member for their direct interengagement with wide angular lost motion, a stationary part adjacent-to said second part and friction means intermediate said stationary part and second part, said cord tensionally reacting on said member and second part to frictionally engage said second part with said friction means and to hold it stationary during the drive of said driven member through said planet means and to provide for slip motion of said second part when said knob and first named part drive directly said driven member.

3. A tuning control device for radio receivers comprising a manipulating knob, a spindle connected with said knob, a stationary part rotatably supporting saidspindle, a hollow driven cooperating with said spindle and rim for planetary operation, a sleeve extending from said rim and embracing said spindle said stationary part and sleeve having cooperating frictional surfaces and said cord tensionally reacting on said driven member, spindle and sleeve to hold said friction surfaces interengaged, and means on said spindle and driven member for their direct interengagement with wide angular lost motion,'said frictionally engaged rim sleeve and stationary part cooperating to hold said rim stationary during the drive of said driven member through said planet balls and to provide for slip motion'of said rim when said knob and spindle drive directly said driven member.

4. A tuning control device for radio receivers comprising a manipulating knob, a spindle connected with said knob, a stationary part rotatably supporting said spindle, a hollow driven member on said spindle and having seats throughout it, a cord operating the radio receiver tuning means and dial and operatively connected with said hoilow member, a rim encircling said driven member, planet balls in said seats and cooperating with said spindle and rim for planetary operation, friction means intermediate said stationary part and rim, a sleeve extending from said rim and embracing said spindle said stationary part and 'sleeve having cooperating frictional surfaces and means operative, means on said spindle and driven member for their direct interengagement with wide angular lost motion, said friction means and surfaces cooperating to hold said rim stationary during the drive of said driven member through said planet balls and to provide for slip motion of said rim when said knob and spindle drive directly said driven member.

5. A tuning control device for radio receivers comprising a manipulating knob, a spindle connected with said knob, a stationary part rotatably supporting said spindle, a hollow driven member on said spindle and having seats throughout it, a cord operating the radio receiver tuning means and dial and operatively connected with said hollow member, a rim encircling said driven member, planet balls in said seats and cooperating with said spindle and rim for planetary operation,asleeveextendinsfrcmsaidrimand embracing said spindle said stationary part and sleeve having cooperating frictional surfaces, friction means intermediate said stationary part and rim and friction means intermediate said stationary part and sleeve, said cord tensionally reacting on said driven member, spindle, rim and sleeve to hold said fn'ction surfaces interengaged and said friction means operative, means on said spindle and driven member for their direct interengagement with wide angular lost motion, said friction means and surfaces cooperating to hold said rim stationary during the drive of said driven member through said planet balls and to provide for slip motion of said rim when said knob and spindle drive directly said driven member.

LEONE KAMENAROVIC. 

